The present invention relates to an apparatus for examining the cardiac pulse frequency. A generally known method of measuring the cardiac pulse frequency consists of measuring the pulse for one minute. In order to shorten this relatively long measuring period, the pulse is often measured for a shorter period, e.g. for 15 seconds, with the resulting number then being multiplied by four. However the accuracy of this method is lower than the accuracy of measuring the heartbeats for one whole minute, as fractions of heartbeats cannot be measured. The number of heartbeats measured within a period of fifteen seconds, for example, can be up to almost one heartbeat too high or too low relative to the actual value, which is too large an error for precise examinations.